Collision detection sensor for vehicle and obstacle discrimination device using the same

Abstract

A collision detection sensor for a vehicle is provided with sensor cells totaling i, which are linearly arrayed with a predetermined pitch in a bumper of the vehicle and arranged in a longitudinal direction of the bumper. The sensor cells respectively detect pressures which are applied to the bumper at different positions thereof due to a collision between an obstacle and the bumper. Wirings of the sensor cells totaling i have a connection relation which is same with that of a n×m matrix wiring arrangement (i≦n×m). Thus, the wiring space can be decreased by a wiring number reduction, so that the vehicle-mounting performance can be improved.

1 . A collision detection sensor for a vehicle, the collision detection sensor comprising 
 sensor cells totaling i (i is an integer larger than or equal to “1”), which are linearly arrayed with a predetermined pitch in a bumper of the vehicle and arranged in a longitudinal direction of the bumper, wherein:    the sensor cells respectively detect pressures which are applied to the bumper at different positions thereof due to a collision between an obstacle and the bumper; and    wirings of the sensor cells have a connection relation which is same with that of a n×m matrix wiring arrangement (n, m is an integer larger than or equal to “2”, and i≦n×m).    
   
   
       2 . The collision detection sensor according to  claim 1 , wherein n is equal to m.  
   
   
       3 . An obstacle discrimination device having at least the one collision detection sensor according to  claim 1 , the obstacle discrimination device further comprising 
 a control unit for sort-distinguishing the obstacle colliding with the bumper of the vehicle based on the pressures detected by the sensor cells.    
   
   
       4 . The collision detection sensor according to  claim 1 , wherein 
 the sensor cell has a pair of conductive ink layers which are respectively formed at two opposite resin films, and a pair of pressure-sensitive ink layers which respectively covers the conductive ink layers and face each other with an inner space therebetween.    
   
   
       5 . The collision detection sensor according to  claim 4 , wherein 
 the pressure-sensitive ink layer has a characteristic that an electrical resistance thereof decreases with an increase of a pressure exerted thereto.    
   
   
       6 . The obstacle discrimination device according to  claim 3 , wherein the collision detection sensor is arranged between a bumper reinforce member and a bumper absorber of the vehicle, the bumper absorber being disposed at a vehicle front side of the bumper reinforce member.  
   
   
       7 . The obstacle discrimination device according to  claim 3 , wherein the collision detection sensor is arranged between a bumper cover and a bumper absorber of the vehicle, the bumper cover being disposed at a vehicle front side of the bumper absorber.  
   
   
       8 . The obstacle discrimination device according to  claim 3 , further comprising 
 a vehicle velocity detection unit for detecting a velocity of the vehicle, wherein    the control unit sort-discriminates the obstacle colliding with the bumper based on a mass of the obstacle, the mass being calculated according to the pressures detected by the sensor cells and the vehicle velocity detected by the vehicle velocity detection unit.    
   
   
       9 . The obstacle discrimination device according to  claim 8 , wherein the vehicle velocity detection unit is constructed of at least one velocity sensor.  
   
   
       10 . The obstacle discrimination device according to  claim 3 , wherein 
 the control unit actuates a pedestrian protection device of the vehicle, when it is determined that the obstacle colliding with the vehicle is a pedestrian.    
   
   
       11 . The obstacle discrimination device according to  claim 3 , wherein the control unit is a signal process circuit.